Sheldon: Can't we just go to Big Boy? They only have one burger: the Big Boy.Penny: The Barbecue Burger is like the Big Boy.Sheldon: Excuse me, in a world that already includes a Big Boy, why would I settle for something that's like a Big Boy?

Sheldon: I need your help in a matter of semiotics.Penny: What?Sheldon: Semiotics, the study of signs and symbols as a branch of the philosophy related to linguistics.Penny: Okay, honey, I know you think you are explaining yourself, but you're really not